Expression of Helicobacter pylori vacuolating toxin in Escherichia coli.

Vacuolating Cytotoxin of Helicobacter pylori

Vacuolating cytotoxin (VacA) is one of the most important virulence factors of H. pylori (Hp), which isthe only toxic protein that is secreted from Hp cell into the culture supernatant. The effects of VacA oneukaryotic systems is the subject of many previous and on going research studies. Intracellular targetsfor this toxin include: late endosomal and lysosomal compartments, m...

Cloning and Expression of the Heterogenic Vacuolating Cytotoxin From an Iranian Helicobacter pylori Strain

Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

Objective(s): Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity.   Materials and Methods: The antigenic region of V...

Vacuolisation of human microvascular endothelial cells by enterohaemorrhagic Escherichia coli.

Enterohaemorrhagic Escherichia coli (EHEC) cause haemolytic uraemic syndrome (HUS), a thrombotic microangiopathy resulting from endothelial injury in the renal glomeruli and other organs. EHEC virulence factors that damage the microvascular endothelium play therefore major roles in the pathogenesis of HUS. We identified an EHEC strain that vacuolates and kills primary human glomerular microvasc...

Helicobacter pylori cytotoxin: importance of native conformation for induction of neutralizing antibodies.

We have attempted to express the Helicobacter pylori vacuolating cytotoxin in Escherichia coli. Although the 95-kDa VacA polypeptide was expressed abundantly, it completely lacked any biological activity. In addition, this material failed to induce neutralizing antibodies after immunization of rabbits. In contrast, highly purified high-molecular-mass cytotoxin from the supernatant of H. pylori ...